Binding From both sides: TolR and full-length OmpA bind and maintain the local structure of the E. coli cell wall
Binding From both sides: TolR and full-length OmpA bind and maintain the local structure of the E. coli cell wall
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DOI：
10.1101/409466
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
Alister Boags;Firdaus Samsudin;S. Khalid
中科院分区：
文献类型：
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作者：
Alister Boags;Firdaus Samsudin;S. Khalid
我们对大肠杆菌进行了分子建模和模拟研究。大肠杆菌细胞膜，特别关注TolR的作用，TolR是大肠杆菌的天然蛋白。大肠杆菌内膜与细胞壁的相互作用。已经提出TolR与肽聚糖结合，但迄今为止该蛋白质的唯一结构是在其中推定的肽聚糖结合结构域不可接近的构象中。我们表明，该结构域暴露的蛋白质的扩展构象的模型，结合肽聚糖主要是通过静电相互作用。我们表明，非共价相互作用的TolR和OmpA与细胞壁，分别从内膜和外膜侧，保持的位置，即使在没有布劳恩的脂蛋白的细胞壁。当OmpA被截短以去除肽聚糖结合结构域时，TolR能够将细胞壁拉向内膜。在我们的模拟中介导TolR的细胞壁相互作用的带电残基在许多革兰氏阴性细菌物种中是保守的。
We present a molecular modeling and simulation study of the of the E. coli cell envelope, with a particular focus on the role of TolR, a native protein of the E. coli inner membrane in interactions with the cell wall. TolR has been proposed to bind to peptidoglycan, but the only structure of this protein thus far is in a conformation in which the putative peptidoglycan binding domain is not accessible. We show that a model of the extended conformation of the protein in which this domain is exposed, binds peptidoglycan largely through electrostatic interactions. We show that non-covalent interactions of TolR and OmpA with the cell wall, from the inner membrane and outer membrane sides respectively, maintain the position of the cell wall even in the absence of Braun’s lipoprotein. When OmpA is truncated to remove the peptidoglycan binding domain, TolR is able to pull the cell wall down towards the inner membrane. The charged residues that mediate the cell-wall interactions of TolR in our simulations, are conserved across a number of species of Gram-negative bacteria.